1. Among the ancients, a cloth of exceedingly fine texture, either of linen, cotton, or silk; a tuft of fibres, by which certain shell-fish are attached to rocks; a tuft.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• vyssus,
• nyssus,
• hyssus,
• gyssus,
• btssus,
• bgssus,
• bhssus,
• bussus,
• b7ssus,
• b6ssus,
• byasus,
• byzsus,
• byxsus,
• bydsus,
• bysus,
• byssuss,
• bysses,
• byssu s,
• bysuses,
• byssuses

The adjective form of "byssus" is "byssal".